assistant2: Suggest current file as context (#22526)

Suggest adding the current file as context in the new assistant panel.



https://github.com/user-attachments/assets/62bc267b-3dfe-4a3b-a6af-c89af2c779a8


Note: This doesn't include suggesting the current thread in the inline
assistant.

Release Notes:

- N/A

crates/assistant2/src/message_editor.rs

@@ -20,7 +20,7 @@ use workspace::Workspace;
 use crate::assistant_model_selector::AssistantModelSelector;
 use crate::context_picker::{ConfirmBehavior, ContextPicker};
 use crate::context_store::ContextStore;
-use crate::context_strip::ContextStrip;
+use crate::context_strip::{ContextStrip, SuggestContextKind};
 use crate::thread::{RequestKind, Thread};
 use crate::thread_store::ThreadStore;
 use crate::{Chat, ToggleContextPicker, ToggleModelSelector};
@@ -87,6 +87,7 @@ impl MessageEditor {
                     Some(thread_store.clone()),
                     editor.focus_handle(cx),
                     context_picker_menu_handle.clone(),
+                    SuggestContextKind::File,
                     cx,
                 )
             }),